The present invention relates to an improved infiltration system for traffic areas such as roadways, train corridors, runways and carparks.
Presently the roadways are based upon the old Roman system of having a water impervious top layer that directs water into side gutters where it passes into underground pipes and drains, which are impervious to water, and is directed from a large catchment area into creeks, rivers and the ocean.
Thus when it rains, all of the rubbish and pollution such as oil, grease, vegetation, dog faeces, food stuffs, paper, dissolved pollutants and detergents, are flushed into the drainage system and concentrated into the outfall area, such as a creek, river and the ocean. There is little or no attempt in most of the existing drainage systems to decontaminate this storm water pollution. If any treatment is carried out, it, usually, only involves a filtering out of larger solids. This dumping of the stormwater runoff into the water ways, degrades the water ways by depleting the oxygen from the waterways, and introduces chemicals which increases, in some cases exponentially, the growth algae, both of which destroys the healthy fauna and flora of the waterways.
Further because the natural water absorbing soils and vegetation have been covered or removed and replaced by water impermeable roads, there is an increase in the amount of runoff in urban areas, than if the area was in its natural state.
Attempts have been made to ameliorate these problems by using permeable drains having a surface of permeable tar or the like. However these do not have a permeability to cope with heavy rain.
Further attempts were made using heavy duty drainage cell filled with gravel or grass as the road or pavement surface. Whilst these provide an improved infiltration, they are difficult to clean by removing litter and rubbish that collects on the surface of the heavy duty drainage cell, without disturbing the gravel or the grass, and decaying litter and rubbish produces anaerobic conditions within the soil and gravel resulting in the growth of anaerobic bacteria, which decreases the permeability of the soil or gravel. Further the drainage cells are not wheel chair friendly and provided difficult surfaces for women with high heel shoes to navigate.